English

Conjectures on representations involving primes

Number Theory 2017-12-04 v9

Abstract

We pose 100 new conjectures on representations involving primes or related things, which might interest number theorists and stimulate further research. Below are five typical examples: (i) For any positive integer nn, there exists k{0,,n}k\in\{0,\ldots,n\} such that n+kn+k and n+k2n+k^2 are both prime. (ii) Each integer n>1n>1 can be written as x+yx+y with x,y{1,2,3,}x,y\in\{1,2,3,\ldots\} such that x+nyx+ny and x2+ny2x^2+ny^2 are both prime. (iii) For any rational number r>0r>0, there are distinct primes q1,,qkq_1,\ldots,q_k with r=j=1k1/(qj1)r=\sum_{j=1}^k1/(q_j-1). (iv) Every n=4,5,n=4,5,\ldots can be written as p+qp+q, where pp is a prime with p1p-1 and p+1p+1 both practical, and qq is either prime or practical. (v) Any positive rational number can be written as m/nm/n, where mm and nn are positive integers with pm+pnp_m+p_n a square (or π(m)π(n)\pi(m)\pi(n) a positive square), pkp_k is the kk-th prime and π(x)\pi(x) is the prime-counting function.

Keywords

Cite

@article{arxiv.1211.1588,
  title  = {Conjectures on representations involving primes},
  author = {Zhi-Wei Sun},
  journal= {arXiv preprint arXiv:1211.1588},
  year   = {2017}
}

Comments

33 pages, final published version

R2 v1 2026-06-21T22:34:24.769Z